Avram Noam Chomsky is an American linguist, philosopher, cognitive scientist, political activist, author, and lecturer. He is an Institute Professor emeritus and professor emeritus of linguistics at the Massachusetts Institute of Technology.

Chomsky was born in the East Oak Lane neighborhood of Philadelphia, Pennsylvania. A graduate of Central High School of Philadelphia, Chomsky began studying philosophy and linguistics at the University of Pennsylvania in 1945. In 1949, he married linguist Carol Schatz. They remained married for 59 years until her death in December 2008. The couple had two daughters. Chomsky received his PhD in linguistics from the University of Pennsylvania in 1955. He conducted part of his doctoral research during four years at Harvard University as a Harvard Junior Fellow.

Chomsky joined the staff of the Massachusetts Institute of Technology (MIT) in 1955 and in 1961 was appointed full professor in the Department of Modern Languages and Linguistics. From 1966 to 1976 he held a Professorship of Modern Languages and Linguistics, and in 1976 he was appointed Institute Professor. As of 2008, Chomsky has taught at MIT continuously for 53 years.

In the 1950s, Chomsky began developing his theory of generative grammar, which has undergone numerous revisions and has had a profound influence on linguistics. He established the Chomsky hierarchy, a classification of formal languages in terms of their generative power. In 1959, Chomsky published a widely influential review of B. F. Skinner's theoretical book Verbal Behavior, which was the first attempt by a Radical Behaviorist to provide a functional, operant analysis of language. Chomsky used this review to broadly and aggressively challenge the behaviorist approaches to studies of behavior dominant at the time and contributed to the cognitive revolution in psychology.

Beginning with his opposition to the Vietnam War Chomsky established himself as a prominent critic of US foreign and domestic policy. He is a self-declared adherent of libertarian socialism which he regards as "the proper and natural extension of classical liberalism into the era of advanced industrial society."